The present invention relates to a drive system, more specifically it relates to a drive system capable of synchronously moving two sliders.
Various drive systems for moving a driven body in a plane have been known. For example, there was disclosed a two dimentional drive system, which defines the position of works or tools, etc. attached on a driven body, in Japanese Provisional Publication (Kokai) Gazette No. 53-36869. The system was a drive system for a working table, and it has a first slider which is moved in a first direction by first driving means, and a second slider as the driven body which is provided on the first slider and is moved in a second direction perpendicular to the first direction by second driving means. Works to be machined or tools, etc. are attached on the second slider, so that they can be moved in a plane and positioned therein. Therefore, this drive system has been used for automated machinery.
However, there are disadvantages in the above noted conventional drive system.
For example, in an automatic chip-inserting machine, which automatically inserts IC-chips in a printed circuit board (PC board), having a conventional drive system, an inserting tool is attached on a driven body and an IC-chip is picked up by the tool. The IC-chip picked up is carried to a prescribed position on the PC board with the movement of the driven body to insert therein. Upon inserting, the PC board is bent downward because of low hardness. When inserting pressure applied to the PC board is too high, the PC board is bent beyond its elastic limit, so that the PC board is sometimes broken. To solve this problem, it is effective to provide a supporting member below the PC board. But it is necessary to change the supporting member or the position thereof when the size or inserting position of the PC boards is changed. Then using two drive systems was proposed. Namely, two drive systems are set apart in the vertical direction, two driven bodies are synchronously moved, and the supporting member is attached on the driven body of the lower drive system. With this structure, the problem is solved but there are other disadvantages: high manufacturing cost and difficult synchronous control of the two driven bodies.